Why tail coreutil cannot work as its input is from tee

[Budi]

How come tail coreutil cannot work as its input is from tee

$ echo -e '9\n4\n3\n2\n8\n7\n3\n1' |tail -1
1

But :

$ echo -e '9\n4\n3\n2\n8\n7\n3\n1' |tee >(head -1) |tail -1
9

Please help explain